a half dozen. half a dozen

Here’s a question I posed this morning to Paul Stregevsky:

Q: Which phrase do you prefer?

1. a half dozen

2. half a dozen

For what it’s worth, “a half dozen” returns 1,580,000,000 results, while “half a dozen” returns 204,000,000.

A: Garner's Modern English partly supports Google::

Half a dozen and a half dozen. For this noun phrase, either half a dozen or a half dozen is good form. The predominant form in print sources has always been half a dozen.

So: To follow tradition, use half a dozen. To embrace the vernacular present and the printed future, use a half dozen.